Oil filter



May 11, 1937. H. G. KAMRATH 2,979,910

om FILTER Filed Aug. 5r, 1935 2 Sheets-Sheet. l

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OIL IIILTER Filed Aug. 5, 1935 2 Sheets-Sheet 2 "sans l inurl lll-lr 1 IJ. '"5 I Illu.. 7`

Patented May 1ls 1937 erases param ori-ics Herbert G. Kamath, Flint, Mich., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 5, 19.135, Serial No. 34,757

3 Claims. (Cl. ZID-205) This invention relates to filters and has par- Figure 4 is a view of the filter before the comticulai` reference to a novel filtering material for pression of the filtering material. use on 011 futers, V Figure 5 is a view similar to Figure 4 but with The novel filtering element of the invention 'the Shaper applied. i,

5 comprises'the use of blast furnace slag in the Figure 6 is a sectional view substantially on '5 form of mineral wool/or rock wool made from the line 6(-6 of Figure 5. natural rock such as limestone. Filters of vari# Figure 'l is a sectional view substantially on ous kinds which make use of mineral wool as a the line 1--1 of Figure 5, but showing the filtering filtering material are very'old and well known, material compressed.

10 but in the prior art the use of this material Referring to the drawings. the numeral 2 indil0 has always been in the statein which it has cates a container of any suitable kind. The conbeen blown, that is, in the fibrous or woolly state. tainer has the bottom opening 4 in which there It has been found that while this material gives is fastened the outlet fitting 6, the fitting having satisfactory filtration, there is some objection a passage therethrough to allow the exit of the '15 to its use in that it is always necessary to use filtered oil. A second opening 8 in the bottom l5 an outer covering or retainer to hold the` wool of the container 2 has the fitting I0 secured in place. If this outer retaining covering is not therein. The fitting l0 is internally threaded used, the filtering material will not hold its shape and receives the drain plug I2. By unscrewing and will fall to the bottom of the filter or rethe plug I2 the filter may be drained. The filter ceptaoie in which it is held. There is also the has the inlet Opening I4 below the upper Aedge 2o thereof.

The cover of the filter is indicated at I6. A flange I8 on the filter cover lits over the upper end of the container and a gasket 20 is applied between the cover and the container to form a v2, liquid tight joint.

Inside the container the central outlet tube 22 is rigidly secured at its lower end in the outlet fitting 6. The tube has the openings 24 therein tendency to float in the filtering liquid and the danger of passing small particles of the slag Wool or mineral wool into the filtered liquid. Additionally, there is the objection that when the filters are being made the light fibers of the mineral wool will float in the air and thus injure the health of the Workmen.

In accordance with the invention the rock wool or mineral wool is mixed with a suitable binder,

such as a solution-ofl silicate of soda or ordinary to allow the filtered oil to enter the tube on its 30 clay and Water, until the mixture is in a mushy Way to the outletiitting 6. The upper end 26 state. A quantity of the mixture is then suitably of the tube is internally threaded to receive the formed to adapt lt to a filter and the liquid of threaded shank of the fitting 28 which extends the binder driven from the mixture by drying, through an opening 30 in the cover I6 and is such as heating in an`oven. After the liquid formed to a polygonal head 32 at its upper end. 3f, has been driven from `the mass, the resultant The polygonal head has a handle 34 passing product is a hard porous mass of mineral wool therethrough to enable the fitting 28 to be turned which is capable of maintaining its own shape into the threaded end 26 of the tube 22. A suitand needs no outer retaining dement. The able gasket 36 is usedbetween the head 32 and 40 mass is suiiiciently porous to give good filtering the '00P 0f the Cover 5 t0 form a' liquid tight 40 and is not likely to channel. By "channe1ing. connection s meant the tendency to form demte passages On the inside of the container the fitting 28 is through the slag wool which will allow unfiltered provlded with 9 groove 38 m wzchhther is re liquid to pass directly through the mter wmp ceived one end of a coil spring 0, t e ot er en of which rests in an annular recess 42 on one of 45 out being properly filtered the end members 44 of a spool or bcbbln shaped on the drawings: element 46 which receives the filtering material Figure l is a view in elevation of a filter in 48. accordance with the invention, lparts being The function of the Spring 40 is to hold the 50 broken away and shown in section to illustrate parts from rattling when in operative position. 50 the construction. By turning the handle 34 the upper fitting 28 Figure 2 is an enlarged sectional view through will be screwed into the threaded end 26 which the filter cartridge or element of the invention. `will compress the coil spring 40 and the gaskets Figure 3 is a section on the line 38 of Fig- 20 and 36 to form a liquid tight connection. A ure l. second end member 68, similar in shape to the 55 end member 44, is used, andthe ytwo are cons nected by the central cylinder 52. The'end members 44 and 50 have central openings to enable them to be passed over the tube 22, and flanges 53 are provided at-the openings. The cylinder 52 comprises the upper imperforate end member 54, the lower imperforate end member 56, and the intermediate perforate member 58. These three members are suitably secured together as by welding at the flanges 50. The perforate member 58 is provided with the openings 59 entirely around its periphery. Suitable jspacers or reinforcing members 62 are secured to the interior ofthe perforate member and have central openings 64 to allow the spool or bobbin shaped element 46 to be passed over the outlet tube 22.

At the lower end of the filter a spacing tube 65 spaces the lower end member from the outlet ilflng 6. The spacer 65 passes freely over the tube 22. A

Suitable handles 66 are secured to the end memberv 44 to allow-for an easy insertion or removal of the filtering spool 46.

A suitable fabric 68 such as Wool felt or canton annel is applied around the cylindrical element 52 before the application of the filtering material 48. 'Ihe purpose of the fabric is to prevent the entrance of any of the filtering medium into the cylinder 58.

The filterng element 48 of the invention comprises either rock wool ornatural blast furnace slag known commercially asmineral or slag wool. This wool is not used on the spool or cartridge as the wool comes from the manufacturer. In its manufactured state it is fibrous Aor stringy and quite brittle, the fibers tending to break and fall to. the bottom of whatever receptacle contains them. In order to retain them on a bobbin or spool such as shown in the figure it is necessary to surround the mineral wool with a covering of a. fabric such as canton fiannel or a wire screen.

This fabric or screen is necessary to retain the filtering medium in itsshape.

In the present instance the wool is first made into a mushy state by-mixing it with a suitable binder, for instance a `thin solution of silicate of soda. After the vmineral wool and binder vare thoroughly mixed and in the mushy state a weighed quantity is suitablyvapplied suchas by handr to the bobbin or spool 46 untilthe spool is substantially filled as shown in Figure '4. A shaper or former in the form of a cylindrical yleldable or flexible metal band is then placed around the spool and wool as shown in Figures 5 and 6. The Shaper '80 has two lugs 8| and B2 secured thereto for theapplication of a suitable tool. vIn Figure 6 it will be noted that the ends 84 and 86 of the shaper'80 overlap. By applying a suitable tool 88, `such as a pair of rpincers, to the lugs 8| and 82 in Figure 6, the end 84 may be drawn toward the lug 82 to compress the wool from the mushy state of Figures 4-6 to the compacted state as is shown in Figures 1-3 and 7. When the pincers are released, the Shaper 80 will expand because of its inherent spring action, thereby enabling the shaper easily to be removed. The wool will retain its compressed state. The filtering cartridge in some cases is then placed in an oven and baked until the liquid of the binder is driven off. Certain clay binders having natural setting property may require little or no heating. The resulting filter element is a hard porous mass of wool which will retain its own shape without the aidy of an exterior covering and is sufliciently porous to give very good filtering service. The binder and the shape and form of the filtering mass will not deteriorate while the filter is in use, but the mass will retain its shape throughout the life of the filter.

Experiment has determined that the addition of the binder and the baking to drive ofi` the liquid does not decrease the filtering ability of the mineral Wool or rock wool. 'Ihe making of the filtering element into the hard porous state will prevent channeling of the filtering material whereby a better filtering results.

If desired, to neutralize-any acidic condition in the oil tobe filtered some trisodium phosphate or other alkaline material may be added to the binder during the mixing operation. However, as some forms of wool are already basic in character, it has been found that it is ordinarily not necessary to add any material to neutralize the acid in the oil.

In operation, assuming the filter-is assembled as shown in Figure 1, the oil or other liquid to be filtered will enter at filtering material 48, then through the perforations 59 in the central element 58, then through the openings 24 in the outlet tube, and then to the outlet fitting 6l If for any reason the filter should be plugged and oil cannot pass through the filtering elen1ent,`a small relief or bypass opening T6 is provided in the fitting 26. rv'Ihis opening connects with a bore 'l2 in the fitting, the bore connecting with the interior of the tube 22. The opening 18 will at all times allow a quantity of unfiltered oil to'` pass through the filter and will prevent the starving of the apparatus to be lubricated due to the filter being plugged.

I claim:

1. A cylindrical filtering element comprising a hard porous mass of mineral wool mixed with silicate of soda. f

2. In a filtering element, a shaped form to receive the element, said form comprising end disks connected by a hollow perforated column, a fabric surrounding the column, and a filtering element comprising a hard porous mass of mineral Wool mixed with silicate of soda surrounding the space around the column and between the disks.

3. A ltering material comprising a hard porous mass of untreated mineral wool mixed with I4 and pass through the 

